Okonite wire and cable - dc resistance of cable conductors
General Conductor Information
dc Resistance

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Based on the resistance-temperature
coefficient of copper of 100 percent
conductivity and of aluminum 61 per-
cent conductivity (international an-
nealed copper standard) at 25C and
the formulas:
R1 = Resistance at 25C
R2 = Resistance at desired temp. T
2  T1 = 25C

Copper        
R
2 = R1  


_VP_EQN_0.GIF



Example:
 
R dc at 75°C for 4/0 AWG
uncoated copper = 0.0509x
1.193 = .0607 ohms/1000ft. 

Aluminum 
R
2 = R1  

_VP_EQN_1.GIF
 
Resistance temperature correction factors
Copper Conductors

Temp. C 

0
10
20

.904
.942
.981

.908
.946
.985

.911
.950
.988

.915
.954
.992

.919
.958
.996

.923
.961
1.000

.927
.965
1.004

.931
.969
1.008

.934
.973
1.012

.938
.977
1.015

30
40
50

1.019
1.058
1.096

1.023
1.062
1.100

1.027
1.066
1.104

1.031
1.069 1.108

1.035
1.073
1.111 

1.039
1.077
1.115

1.042
1.081
1.119

1.046
1.085
1.123

1.050
1.089
1.127

1.054
1.092
1.131

60
70
80

1.135
1.173
1.212

1.139
1.177
1.216

1.143
1.181
1.220

1.146
1.185
1.224

1.150
1.189
1.227

1.154
1.193
1.231

1.158
1.197
1.235

1.162
1.200
1.239

1.166
1.204
1.243

1.170
1.208
1.247

90
100
110

1.250
1.289
1.328

1.254
1.293
1.331

1.258
1.297
1.335

1.262
1.300
1.339

1.266
1.304
1.343

1.270
1.308
1.347

1.274
1.312
1.351

1.277
1.316
1.354

1.281
1.320
1.358

1.285
1.324
1.362

120
130
140

1.366
1.405
1.443

1.370
1.408
1.447

1.374
1.412
1.451

1.378
1.416
1.455

1.381
1.420
1.459

1.385
1.424
1.462

1.389
1.428
1.466

1.393
1.432
1.470

1.397
1.435
1.474

1.400
1.439
1.478

150

1.482

1.480

1.489

1.493

1.497

1.500

1.505

1.509

1.513

1.516

 
Aluminum Conductors

Temp. C 

0
10
20

.901
.940
.980

.905
.944
.984

.909
.948
.988

.913
.952
.992

.917
.956
.996

.921
.960
1.000

.925
.964
1.004

.928
.968
1.008

.932
.972
1.012

.936
.976
1.016

30
40
50

1.020
1.060
1.100

1.024
1.064
1.104

1.028
1.068
1.108

1.032
1.072 1.112

1.036
1.076
1.116

1.040
1.080
1.120

1.044
1.084
1.124

1.048
1.088
1.128

1.052
1.092
1.132

1.056
1.096
1.136

60
70
80

1.140
1.180
1.219

1.144
1.184
1.223

1.148
1.187
1.227

1.152
1.191
1.231

1.156
1.195
1.235

1.160
1.199
1.239

1.164
1.203
1.243

1.168
1.207
1.246

1.172
1.211
1.250

1.176
1.215
1.254

90
100
110

1.258
1.297
1.336

1.262
1.301
1.340

1.266
1.304
1.343

1.270
1.308
1.347

1.274
1.311
1.351

1.278
1.315
1.355

1.281
1.319
1.359

1.285
1.324
1.362

1.289
1.328
1.366

1.293
1.332
1.370

120
130
140

1.374
1.413
1.452

1.378
1.417
1.456

1.381
1.420
1.459

1.385
1.424
1.463

1.389
1.428
1.467

1.393
1.432
1.471

1.397
1.436
1.475

1.401
1.440
1.479

1.405
1.444
1.483

1.409
1.448
1.487

150

1.491

1.495

1.498

1.502

1.506

1.510

1.514

1.518

1.522

1.526


ENGINEERING TECHNICAL CENTER

Every effort has been made to ensure the accuracy of this presentation.
However, information is subject to change. Not responsible for typographical errors.

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Ramsey, New Jersey 07446
Phone 201-825-0300
Fax 201-825-3524
info@okonite.com

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